Dates on chart are not in chronological order

[Tlewman]

I have created a bar/line chart on 2 axis to show the relationship between two different fields over a series of days. I am charting this data by day and have added the prompts- between [Start Date] and [End Date]. When I request data between 12/01/04 and 1/04/05, it brings the data back but it places the Jan 05 days first on the chart, followed by my Dec 04 data. The Date field is formatted as Short Date. What am I doing wrong???
Thanks in advance!